1. Field of the Invention
The present invention relates to an apparatus for cleaning a lubricant for dry type wire drawing, and more particularly to an apparatus for cleaning a lubricant for dry type wire drawing, which can effectively remove a lubricant remaining on a surface of a steel wire or an aluminum clad wire for power lines.
2. Description of the Related Art
Generally, an aluminum clad steel wire (AW) for power lines is provided in such a form that a steel wire has an aluminum cladding on its surface, whereby the steel wire inside of the aluminum clad steel wire acts to increase the tensile strength of the steel rod and the aluminum cladding on the surface of the steel rod mainly act as an electric conductor.
Several aluminum clad steel wires are stranded and used for aerial cables, which are power lines for high voltage transmission.
As for one of conventional methods of applying the aluminum cladding on the surface of the steel wire, a continuous extrusion method is used. The aluminum clad steel wire produced by the continuous extrusion method is drawn into a steel wire having a desired diameter according to the diameter of the steel wire through several steps of a wire drawing process.
Generally, the wire drawing method can be classified into a wet type wire drawing method and a dry type wire drawing method.
First, the wet type wire drawing method is performed such that a steel rod is drawn by passing through a wire drawing die in a state that pressure is applied to a lubricant in a liquid state with a pressure die. Thus, when a weak pressure is applied to the lubricant, the dies are easily broken.
Further, it is difficult to keep the pressure of the lubricant in a predetermined state using the pressure die, and the wet type wire drawing method is mainly used for low speed wire drawing.
Compared with the wet type wire drawing method, the dry-type wire drawing method uses a lubricant comprising soap components (KaOH+NaOH) not in a liquid state but in a solid state. Thus, it is easy to apply pressure to the lubricant and to keep the pressure of the lubricant in a predetermined state due to the solid lubricant. Thus, since the dies are not broken during high-speed wire drawing, this method is widely used for high-speed wire drawing at around 400 mpm.
Specifically, the lubricant for the dry type wire drawing generally comprises the soap components mixed in a particular ratio for the wire drawing. The soap components comprise KaOH and NaOH mixed in a predetermined ratio.
The lubricant of the soap components consists of particles of a predetermined size. Specifically, the particle has a size of dozens of microns to several millimeters.
In general, prior to the wire drawing, a main lubrication system is operated in such a manner that as the wire material passing through the lubricant container advances, the lubricant is moved by a force attributed to friction between the wire material and the dry lubricant applied to the surface of the material.
As a result, the lubricant on the wire material is mainly accumulated at an outlet of the lubricant container along with the surface of the wire material, that is, at an inlet of the pressure die or the wire drawing die. Then, a part of the accumulated lubricant passes through the inside of the die, such as a reduction part and a bearing part of the die, along with the wire material, minimizing the friction between the material and the die.
After wire drawing, although it does not always happen, the lubricant often remains in some quantity on the surface of the wire material, causing scattering of the lubricant during post processing, such as strand processing, resulting in the environment contamination.
As for a method of removing the lubricant for the conventional AW dry-type wire drawing, there are various methods as follows.
One of the methods uses some pieces of cloth for cleaning the lubricant. By the method, after the wire drawing is finished, the wire material passes through the center of the pieces of the cloth heaped in place to form many folds so that the lubricant can be naturally cleaned.
Another method uses water for cleaning the lubricant. As the method using the water, there have been suggested a manner wherein the lubricant can be naturally cleaned mainly with warm water while the wire material passes through the warm water bath, a manner wherein the lubricant is cleaned by water injected at a high pressure through a nozzle, a manner of cleaning the lubricant with a rotating brush, or the like.
Among the conventional methods of cleaning the lubricant for the dry-type wire drawing, the method using the pieces of cloth has problems in that although this method can be applied to the low speed wire drawing, when the wire drawing is performed at 400 mpm or more, the cleaning is minimally carried out and the pieces of cloth must be frequently replaced with a new cloth.
In case of the method of cleaning the lubricant in the warm water bath, there occurs no problem when wire drawing at a low speed. However, in case of the high speed wire drawing of 400 mpm or more, cleaning is not adequately carried out and the water bath should be made to have a length of 5 m˜10 m. Further, even if the long water bath is provided, it frequently happens that cleaning is not perfectly carried out.
The methods using the high-pressure injection nozzle and the rotating brush have problems in that cleaning is not adequately carried out and that the cleaning water is easily polluted due to adhering of the lubricant to the cleaning water, so that supply and drainage paths can be blocked by the polluted cleaning water.